System and method for clipping values of pixels in one color space so not to exceed the limits of a second color space

Abstract

A system and method that detects when pixels from one color space would exceed the range of a second color space, and restrict the range of the pixels without distorting their brightness, while preserving their color. The method may provide the ability to restrict the range of pixels in the first color space that may ordinarily transform to “illegal” values with erroneous brightness in the second color space, to a sub-space containing the entire second color space, while preserving the brightness of the pixels. The parameters used to define the sub-space may be programmable. The first color space may be YCrCb and the second color space may be RGB.

1. A method that keeps pixels from a first color space in the range of a second color space, wherein the pixels have a color and brightness, the method comprising:
 detecting when pixels in the first color space exceed the range of pixels in the second color space with a circuit; 
 restricting the pixels in the first color space to the range of the second color space; 
 defining a sub-space within the first color space using a set of parameters; and 
 determining whether a pixel is outside the sub-space or inside the sub-space, wherein the sub-space approximates the range of the second color space and comprises values from the first color space that are outside the second color space; and 
 wherein defining the sub-space within the first color space further comprises determining values in the first color space that correspond to the boundaries of the sub-space comprising values from the first color space that are outside the second color space. 
 
     
     
       2. The method according to  claim 1  wherein the restricting comprises, when a pixel is inside the sub-space keeping the pixel unchanged, wherein the pixel inside the sub-space has brightness and color that do not visually deviate when mapped to the second color space. 
     
     
       3. The method according to  claim 1  wherein the restricting comprises, when a pixel is outside the sub-space:
 forcing the pixel to a new pixel in the sub-space, wherein the brightness and color of the new pixel is not visually deviated from the brightness and color of the pixel from the first color space; and 
 wherein the new pixel inside the sub-space has brightness and color that do not visually deviate when mapped to the second color space. 
 
     
     
       4. The method according to  claim 1  wherein the set of parameters is programmable. 
     
     
       5. The method of  claim 4 , wherein the sub-space in the first color space is larger than a unit cube in RGB color space. 
     
     
       6. The method according to  claim 1  wherein the first color space is YCrCb color space. 
     
     
       7. The method according to  claim 1  wherein the second color space is RGB color space. 
     
     
       8. The method of  claim 1 , wherein if the pixel is outside the sub-space, clipping the pixel to the sub-space. 
     
     
       9. The method of  claim 1 , wherein the sub-space in the first color space is larger than a unit cube in RGB color space. 
     
     
       10. A system that keeps pixels from a first color space in the range of a second color space, wherein pixels have a color and brightness, the system comprising:
 at least one processor capable of detecting when pixels in the first color space exceed the range of pixels in the second color space; 
 the at least one processor capable of restricting the pixels in the first color space to the range of the second color space; and 
 wherein brightness of the restricted pixels is preserved, wherein the at least one processor: 
 defines a sub-space within the first color space using a set of parameters, wherein defining the sub-space within the first color space further comprises determining values in the first color space that correspond to the boundaries of the sub-space; and 
 determines whether a pixel is outside the sub-space or inside the sub-space, wherein the sub-space approximates the range of the second color space and comprises values from the first color space that are outside the second color space; and 
 wherein the sub-space in the first color space is larger than the unit cube in RGB color space. 
 
     
     
       11. The system according to  claim 10  wherein, the at least one processor keeps the pixel unchanged when the pixel is inside the second color space, wherein the pixel inside the sub-space has brightness and color that do not visually deviate when mapped to the second color space. 
     
     
       12. The system according to  claim 10  wherein, when a pixel is outside the sub-space, the at least one processor:
 forces the pixel to a new pixel in the sub-space, wherein the brightness and color of the new pixel is not visually deviated from the brightness and color of the pixel from the first color space; and 
 wherein the new pixel inside the sub-space has brightness and color that do not visually deviate when mapped to the second color space. 
 
     
     
       13. The system according to  claim 10  wherein the first color space is YCrCB color space. 
     
     
       14. The system according to  claim 10  wherein the second color space is RGB color space. 
     
     
       15. The system of  claim 10 , wherein if the pixel is outside the sub-space, clipping the pixel to the sub-space. 
     
     
       16. A memory having stored thereon, a computer program having at least one code section that keeps pixels from a first color space in the range of a second color space, wherein pixels have a color and brightness, the at least one code section being executable by a machine for causing the machine to perform steps comprising:
 detecting when pixels in the first color space exceed the range of pixels in the second color space; 
 restricting the pixels in the first color space to the range of the second color space; and 
 wherein brightness of the restricted pixels is preserved, wherein the code for restricting the pixels comprises: 
 code for defining a sub-space within the first color space using a set of parameters, wherein defining the sub-space within the first color space further comprises determining values in the first color space that correspond to the boundaries of the sub-space; and 
 code for determining whether a pixel is outside the sub-space or inside the sub-space, wherein the sub-space approximates the range of the second color space and comprises values from the first color space that are outside the second color space. 
 
     
     
       17. The memory according to  claim 16  wherein the code for restricting the pixels further comprises code for keeping the pixel unchanged when the pixel is inside the second color space, wherein the pixel inside the sub-space has brightness and color that do not visually deviate when mapped to the second color space. 
     
     
       18. The memory according to  claim 16  wherein the code for restricting the pixels further comprises, when a pixel is outside the sub-space:
 code for forcing the pixel to a new pixel in the sub-space, wherein the brightness and color of the new pixel is not visually deviated from the brightness and color of the pixel from the first color space; and 
 wherein the new pixel inside the sub-space has brightness and color that do not visually deviate when mapped to the second color space. 
 
     
     
       19. The memory of  claim 16 , wherein if the pixel is outside the sub-space, clipping the pixel to the sub-space. 
     
     
       20. The memory of  claim 16 , wherein the sub-space in the first color space is larger than a unit cube in RGB color space.